JPH01319074A - Bucket roller for developing device - Google Patents

Abstract

PURPOSE:To prevent staying of a developer by forming the outer peripheral margin of the no-bucket fitting section of the bucket supporting body of the roller thinner in thickness than the bucket fitting section of the supporting body. CONSTITUTION:At the outer peripheral margin of a flange 53, the plate thickness T1 of the no-bucket 54 fitting section is made thinner than that T2 of the bucket 54 fitting section and a slope section 53a is formed toward the inside. A scraped-off developer moves along the slope section 53a from the outer peripheral margin and is fetched into a bucket roller 55. Therefore, the scraping-off operation of a scraping-off section 55 or scraping-off member 60 is not interfered at the extent corresponding to the thickness of the outer peripheral margin of the no-bucket fitting section of the flange 53 even when the bucket fitting section is thick in thickness and the developer is efficiently scraped off. Thus staying of the developer can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a bucket roller of a developing device used in a copying machine or the like.

(Prior Art) Conventionally, as shown in FIG. 8, for example, a developing device includes a developing sleeve (81) that faces a photosensitive drum (100) in a developing device (80), and a developing sleeve (81) that faces a photosensitive drum (100). There is one in which a bucket roller (82) adjacent to the same-polarity magnetized portion (s t) and (s 3) is accommodated. The bucket roller (82) of this developing device has an abbreviated or U-shaped bucket (83) arranged around its outer periphery, and a developing sleeve (82).
The developer separated and collected from the developer sleeve (81) is mixed and stirred together with the developer stored in the developer stirring tank (84) to improve the potential of the toner.
1).

(Problem to be solved by the invention) However, in the same polar magnetized portions (S3) at both ends of the developing sleeve (81), the lines of magnetic force between the magnetic poles (S,) and (N,) The bucket roller (8
There was a problem in that the conveyance to the stirring tank (84) was poor due to the pressure applied by the rotational pressure of the bucket (83) in 2) and the developer's own weight.

Further, since there are flanges formed at a predetermined thickness to support the bucket (83) at both ends of the bucket roller (82) that are opposite to both ends of the developing sleeve (81), this thickness Since the flow of the developer scraped off within the corresponding range is obstructed by the flange, there is a problem that the scraping performance of the developer separated from the phenomenon sleeve (81) and collected is poor at this part. Ta.

Furthermore, there was a problem in that the developer could become clogged between the flange and the wall of the stirring tank (84), or it could flow to the side of the flange, causing the bearing to enter the area and increasing the driving torque of the bucket roller (82). .

As a result, developer tends to accumulate at both ends of the developing sleeve, causing overflow or backflow.

Therefore, it is conceivable to increase the length of the developing sleeve (81) so that the developer can be collected and supplied in a portion not affected by the disturbance of the magnetic field. However, this has the disadvantage that the developing device becomes larger.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a bucket roller of a developing device that has good developer conveyance and scraping properties at both ends of a developing sleeve.

(Means for Solving the Problems) In order to achieve the above object, the present invention takes in the developer collected from the developing sleeve, mixes and stirs it together with the developer stored in the developer stirring tank, and creates a developing sleeve. In a bucket roller of a developing device for supplying to the developing device, the outer peripheral edge of the bucket non-attached portion of the bucket support of the bucket roller is formed to be thinner than the bucket attached portion.

(Function) According to the above configuration, since the thickness of the outer periphery is thin within the range corresponding to the thickness of the outer periphery of the bucket non-attaching portion of the bucket support, even if the bucket attaching portion wears out quickly, The scraped developer is taken in on both sides or one side of the outer peripheral edge.

(Example) The present invention will be described below with reference to the accompanying drawings.

② Structure of developing device [i) Schematic structure FIG. 1 shows a developing device (1) according to the present invention, and this developing device (1) roughly consists of a toner replenishing device (2) and a developing device (3). It consists of

[ii) Toner supply bag w (2) In the toner supply device (2), the cartridge housing section (4)
A toner cartridge (15) is installed in the.

The cartridge accommodating portion (4) has a rear wall (7), a support member (6a), ( 6b), (
6C) across the rack, supporting members (6a), ~, (6c)
supports a substantially semicircular bottom plate (9). Note that the bottom plate (9) has its tip locked to the arm (11),
The arm (11) has a shaft (10) on the side plates (5), (5).

It is rotatably attached via (10). Further, one end of a spring (I2) is locked to the bottom of the bottom plate (9) and biased in the direction of arrow (a), and when the toner cartridge (15) is not installed, the spring (12)
It moves in the direction of arrow (a) due to the urging force of , and closes the toner supply port (27) of the developing device (3), which will be described later.

The toner cartridge (15) has a stirring blade (18) inserted through a support shaft (17) into a cylindrical body (16) with both ends closed.
The main body (16) has an opening (19) formed along the axial direction.

The toner cartridge (15) has side plates (5), (5)
), the support shaft (17) is lowered along the guide portions (13), (13) formed in Supply port (2
7).

When the toner cartridge (15) is installed, the bottom @ (9
) moves in the direction of the arrow (ao) about the shaft (10) against the biasing force of the spring (12), and the toner supply port (27) is opened.

Note that the toner cartridge (15) is prevented from falling off by a lock portion (8) provided on the rear wall (7).

Further, when the toner cartridge (15) is installed, the handle (4a) located in the cartridge accommodating portion (4) is rotated in the direction of arrow (h) and placed in a position out of the way.

[iii) Developing device (3) The developing device (3) is roughly composed of a toner supply section (20), a developing section (35), and a developer stirring section (45).

(B) Toner supply section (20) The toner supply section (20) receives toner supplied from the toner cartridge (15) of the toner supply device (2) and supplies it to the development section (35). It is.

In the toner supply section (20), between the bottom frame (21) constituting the developing device (3) and the partition walls (49) and (5α) that partition the developer stirring section (45), A toner supply roller (22) is arranged at the front, and a toner hopper (25) having a stirring blade (26) is formed at the rear.

The toner supply roller (22) has minute irregularities formed on its outer circumference, and partition walls (
50), the blade (2) attached to the bottom frame (21)
3) The tips of the toner outflow prevention plates (24) are pressed into contact with each other.

Note that the toner supply roller (22) is connected to an AC power source (31).
) and the recovery bias voltage (Vs) from the DC power supply (32).
(-Vrms +Vss) is applied.

The toner hopper (25) is directed diagonally upward (28)
is connected to the toner supply port (27) via the toner supply port (27), and
28), the toner empty detection device (30) rotates 1.
It is set in Noh. In addition, a toner spill prevention sheet (29) is attached to the lower edge of the toner supply port (27).
The tip contacts the outer periphery of the toner cartridge (15) to prevent toner from spilling out from the gap between the developing device (3) and the toner cartridge (15).

(b) Developing section (35) The developing section (35) not only receives and takes the toner supplied from the toner supply section (20), but also conveys the toner and carrier while driving the photosensitive drum, which is an electrostatic latent image carrier. Toner is supplied to the electrostatic latent image formed on the surface of (100).

In the developing section (35), the space formed between the bottom frame (21) and the sleeve cover (36) includes a developing sleeve (37) at the bottom and another developing sleeve (39) at the top.
), the lower developing sleeve (37) faces the toner supply roller (22) with a predetermined minute gap, and the upper developing sleeve (39) has a sleeve cover (36) on the top. The height regulation plate attached to the rear (
The tips of 41) are opposed to each other with a predetermined height regulating gap.

In addition, the developing sleeves (37) and (39) are connected to a DC power source (4).
2), (43), the developing bias voltage (vb, ), (
vb2) are applied respectively. Further, the developing sleeves (37) and (39) include the developing sleeves (37) and (39).
) and (39), magnet bodies (38) and (40) are housed in a fixed state.

The magnet body (38) has magnetic poles (N,) to (N,) and (Sl
) to (S, ), and the magnetic pole (S,) is connected to the photoreceptor drum (1
00), the magnetic pole (S, ) is arranged in the facing part (B) with the toner supply roller (22), and the magnetic pole (N3
).

(N,) are arranged adjacent to each other on both sides of the position (F) closest to the developing sleeves (37) and (39), and the magnetic i(N,
) and (N, ) are respectively arranged between the magnetic poles (S +) and (N2) and between the magnetic poles (S, ) and (N3).

The other magnet body (40) has magnetic poles (N,) to (N,)
and (S,) to (N4), the magnetic pole (N1) is arranged at the part (D) facing the photoreceptor drum (100),
The magnetic poles (S, ) and (N3) of the same polarity are arranged adjacent to each other to face the developer stirring section (45), and the magnetic poles (s+) and (Nt) are arranged on both sides of the sleeve closest position (P). Magnetic pole body (3
8), the magnetic poles (N3) and (N3) are arranged adjacently so that the different polarities face each other. Further, the magnetic pole (N,) is arranged near the facing portion of the height regulating plate (41), and the magnetic pole (N4) is arranged between the magnetic poles (N,) and (N,).

Further, at both ends of the upper developing sleeve (39), there is an area extending between the developing sleeve (39) and the bucket roller (51) and from the height regulating plate (41) to the vicinity of the tip of the partition wall (50). Covers (70), (70) covering the developing sleeve (39) are provided at regular intervals from the surface of the developing sleeve (39).

These covers (70), (70) cover the bucket roller (5).
This prevents the developer supplied from 1) to the developing sleeve (39) from adhering to the developing sleeve (39) along the direction of the arrow (■).

This prevents the rotational pressure of the bucket roller (5) and the pressure due to the developer's own weight from being applied to the same-polarity magnetized portions (s*) and (S3) at both ends of the developing sleeve (39). The accumulation of agent is suppressed.

(c) Developer stirring section (45) The developer stirring section (45) mixes the toner supplied from the toner supply section (20) to the developing section (35) with the developer whose toner concentration has decreased. The developer is raised to a predetermined concentration and a developer suitable for development is prepared.

In the developer stirring section (45), the stirring tank (46) is formed behind the developing sleeve (39), with an upper frame (47) at the top and partition walls (49) and (5) at the back and bottom.
0), which accommodates a bucket roller (51), and the front part of the partition wall (50) is covered with a developing sleeve (3).
7) and (39) are opposed to each other.

The bucket roller (51), as shown in FIG.
Flanges (53), (53) are fixed to a drive shaft (52) rotatably supported at both ends by side plates (5), (5), and four buckets are placed between the flanges (53), (5a). (54
) was constructed.

As shown in FIG. 3, this bucket (54) is made by bending a rectangular temporary part into a crank-shaped cross section, and has a scraping part (55) which is a side end part and a guide part (which is a flat part in the figure). 56) and
A collision part (57) is a part that stands up vertically from the guide part (56), and a plurality of openings (58) are formed in the longitudinal direction at the part where the guide part (56) intersects with the collision part (57).
It was formed by And this bucket (54
) is installed so that the scraping part (55) faces the rotational direction (g) of the bucket roller (51) and is close to the partition walls (49) and (50), as shown in FIG. ing.

Furthermore, as shown in FIG. 4, among the buckets (54), the guide portions (56) of the pair of opposing buckets (54), (54) are provided with a scooping portion as shown in FIG. (55
) A plurality of inclined guide plates (59) are erected in the elongated direction. This pair of buckets (54), (
The inclined guide plate (5) of one of the buckets (54)
9) and the inclined guide plate (59) of the other bucket (54) are arranged in directions that intersect with each other, and the bucket roller (54)
1) The developer inside is circulated in the axial direction based on its rotation.

As shown in Fig. 2, the outer peripheral edges of the flanges (53), (53) are such that the plate thickness T of the non-attached part of the bucket (54) is thinner than the plate thickness T of the attached part of the bucket (54). Moreover, an inclined portion (53a) is formed toward the inside. Further, the portion of the bucket (54) that intersects with the scraping portion (55) is a wedge-shaped intake portion (53b) cut out so as to be inclined inward.

Both ends of the bucket (54), that is, the developing sleeve (39)
As shown in FIG. 2, a scraping member (60
) is provided protrudingly. This scraping member (60) is a thin plate, such as Mylar film, which is softer and more flexible than the partition walls (49) and (50), and has a flange (50).
3), the attachment of (53) has a width W of 13 or more in plate thickness, and the tip is a partition wall (49).

(50). Also,
A trapezoidal escape hole (61) is provided in the guide portion (56) of the bucket (54) near the scraping member (60) and at the back of the intake portion (53b) of the flange (53).

On the other hand, the lid (4) of the upper frame (47) is placed in the stirring tank (46).
8) is opened and a starter containing toner and carrier mixed in a predetermined ratio is loaded.

Further, a two-component developer containing a mixture of toner and carrier is held on the outer periphery of the developing sleeves (37) and (39).

When installed in an image forming apparatus such as a copying machine, a stirring blade (18) is used as a developing device, which consists of more than just the operation of the developing device.

(26), toner supply roller (22), developing sleeve (
3, 7), (39), and a bucket roller (51) are each drivingly connected to a drive system (not shown).

When the developing device (1) starts driving, the stirring blade (18) moves in the direction of the arrow (b) in the toner cartridge (15).
') direction, and the toner is mixed and stirred while passing through the opening (19) and the toner supply port (27) to the path (28).
).

The toner sent to the toner hopper (25) is transported by a stirring blade (
26), the toner is mixed and conveyed forward while being mixed based on the rotation in the direction of the arrow (d), and is held on the surface of the toner supply roller (22) in the area (A) near the outer circumference of the back surface of the toner supply roller (22). Based on the rotation, it is transported in the direction of arrow (C), and the amount of transport is regulated at the portion facing the blade (23). The toner scraped off from the outer periphery of the toner supply roller (22) by the tip contact portion of the blade (23) stays in the toner hole 7<(25). On the other hand, the toner that has passed through the tip contact portion of the blade (23) is conveyed to the toner supply area ([3) where the developing sleeve (37) and the toner supply roller (22) face each other, and here The scraping action of the carrier and developer conveyed in a magnetic brush state based on the rotation in the direction of arrow (e), the development bias voltage (vb,) and the collection atomization pressure (Vss) (=Vrms +vss) The developing sleeve (37) is supplied to the outer periphery of the developing sleeve (37) by electrostatic attraction based on the potential difference between the developing sleeve (37) and the developing sleeve (37).

In addition, in the toner supply area (B), in parallel with the toner supply operation, an operation is performed to collect excess toner on the developing sleeve (37) to the toner supply roller (22) by the electrostatic attraction force, and the developing sleeve (37) The toner concentration of the developer held on the carrier (toner content relative to carrier) is maintained at a predetermined value.

Further, the toner collected by the toner supply roller (22) is conveyed in the direction of arrow (c), and the toner is transported to the toner outflow prevention plate (24).
) and are collected in the toner hopper (25).

The toner supplied to the surface of the developing sleeve (37) is taken in by the developer held in a magnetic brush state, and while being mixed with the developer, the developer flows based on the rotation of the developing sleeve (37). Refer to 4th reference] Along arrow (e)
During the conveyance process, the developer and toner are mixed microscopically based on the rotational force of the developing sleeve (37) and the magnetic force of the magnet (38), thereby improving their respective potentials.

The developer flowing on the developing sleeve (37) and being conveyed along the direction (3) reaches the part facing the developing sleeve (39), where the magnetic pole (S3) of the developing sleeve (37) and the developing sleeve (3
The developing sleeve (39) is attracted to the magnetic pole (N,) based on the lines of magnetic force generated between the developing sleeve (37) and the developing sleeve (39).
) to metastasize above.

The developer transferred to the developing sleeve (39) flows along the rotation of the developing sleeve (39) and is conveyed in the direction of the arrow (f) along the magnetic pole (St) and (S3).
The developing sleeve (39) is separated from the outer periphery of the developing sleeve (39) at the non-magnetic pole portion (C) formed between the developing sleeve (39) and collected in the stirring tank (46).

Note that the developer conveyed from the direction of arrow (e) along the developing sleeve (37) is
At the opposite portion of (39), the developer suddenly changes direction and heads in the direction of arrow (f), so that the developer is properly mixed and stirred here.

The developer separated from the developing sleeve (39) and collected is
Based on the rotation of the bucket roller (51) in the direction of arrow (g), the partition wall (49), (
50) Flow over. Then, the developer is placed in a bucket (54
) is scraped off by the scraping part (55) of the guide part (56
) flows into the bucket roller (51) in the direction of arrow (i), the flow direction is slightly changed by the inclined guide plate (59) and collides with the collision part (57), where it is mixed and agitated while flowing into the bucket roller (51). Bucket roller (51) along the D direction
The flow is divided into one flow toward the inside of the bucket roller (51) and one flow toward the outside of the bucket roller (51) from the opening (58) along the direction of arrow (k).

The developer headed inside the bucket roller (51) along the direction of arrow (D) flows into a pair of opposing buckets (54), (
Since the toner is further mixed and agitated while being circulated in the axial direction by the inclined guide plates (59) and (59) provided in the toner (54), uneven supply of toner and deviation of the developer are eliminated. The developer mixed and stirred in this way is charged to a predetermined charge and is discharged in the flow direction from the gap or opening (58) between the buckets (54) and (54) in the upper part of the figure. be done.

Also, along the arrow (k) direction, the bucket roller (5I)
The developer flowing outside flows out from the opening (58) and is scraped off by the L-shaped recess (54a) on the outer surface of the bucket (54) together with the developer that was not scraped off, and is transported in the direction of the arrow (■). Alternatively, it is scraped off by the scraping part (55) of the succeeding bucket (54) and flows in the same manner as described above.

The developer in the stirring tank (46) around the bucket roller (51) is scraped by the L-shaped recess (54a) of the bucket (54) and released toward the developing sleeve (39) in the flow direction. Ru.

On the other hand, at both ends of the developing sleeve (39), as shown in FIG.
The developer separated along the direction has poor fluidity due to disturbances in the magnetic field and the like.

However, as shown in FIG. 5, the developer in this area is scraped off in the direction of the arrow (12) by the scraping member (60) of the bucket (54) of the bucket roller (51), forming a wedge-shaped intake portion ( 53b). This intake part (53b
) has an inclined surface that goes toward the inside of the bucket roller (51), so the developer here goes toward the inside of the bucket roller (51) along the direction of the arrow (m). As a result, the developer at both ends of the developing sleeve (39) is transferred to the stirring tank (
46), and there is no accumulation of developer, backflow to the lower developing sleeve (37), spillage, etc.

Further, when the developer is compressed and the pressure increases in the intake part (53b), a part of the developer leaks in the direction of arrow (n) through the escape hole (6). )
The developer from the intake portion (53b) is not clogged, and an increase in the torque of the drive shaft (52) is avoided.

Further, the developer scraped off by the scraping portion (55) or the scraping member (60) of the bucket (54) is likely to be disturbed by the outer peripheral edge of the bucket non-attached portion of the flange (53), (53). However, since the outer periphery of the non-bucket attachment part is thinner than the bucket attachment part, it flows from the outer periphery along the sloped part (53a) and flows to the bucket roller (55).
taken within. As a result, the flange (53), (
Even if the thickness of the bucket attachment part is thick, scraping by the scraping part (55) or the scraping member (60) will not be prevented within the range corresponding to the thickness of the outer peripheral edge of the bucket non-attaching part of 53). Don't worry, it will be scraped off efficiently. Also,
Since the bucket attachment portions of the flanges (53) and (53) are thick, the attachment strength will not be reduced.

The developer mixed and stirred in the stirring tank (46) flows as
(see Figure 4) toward the developing sleeve (39), and a part of it is held on the surface of the developing sleeve (39) again at the part facing the magnetic poles (S,), (N,). (
r) direction, and the amount of conveyance is regulated at the portion facing the height regulating plate (41).

The developer that has passed through the part facing the height regulating plate (41) is conveyed in the direction of the arrow (r) in the state of a magnetic brush, and the flow
The electrostatic latent image formed on the outer peripheral surface of the photoreceptor drum (100) is rubbed in the developing area (D) where the photoreceptor drum (100) and the developing sleeve (37) face each other along the This is then visualized as a toner image.

The developer that has passed through the development area (D) is transferred to the development sleeve (3).
9), the magnetic pole (Sl) of the developing sleeve (39) and the magnetic pole (N3) of the developing sleeve (37) The magnetic pole (N
a) and transferred to the developing sleeve (37) without entering between the developing sleeves (39) and (37).

The developer transferred to the surface of the developing sleeve (37) is conveyed in the direction of the arrow (e) based on the rotation, and comes into contact with the electrostatic latent image on the photoreceptor drum (100) again in the developing area (E). Toner is again supplied to the toner image visualized in the development area (D). Therefore, toner is replenished even in areas where toner supply was insufficient in the development area (D).
There will be no density unevenness or white spots due to insufficient toner supply.

The development in the development areas (D) and (E) is performed using the development bias voltages (vb t) and (vb +) applied to the development sleeves (39) and (37) and the photoreceptor drum (100).
) and the surface potential.

The developing agent that has passed through the development area (E) is conveyed along the flow (see Figure 4) to the part facing the toner supply roller (22), where an amount of toner corresponding to the amount consumed by development is collected. Supplied.

The supplied toner is conveyed along the outer peripheral surfaces of the developing sleeves (37) and (39) as described above.

By repeatedly performing development as described above, the toner in the toner cartridge (15) is gradually consumed, and along with this, the toner hopper (25) and the path (28) are consumed.
) decreases, the toner empty detection device (30) rotates in the direction of arrow (i) to detect that the toner cartridge (15) should be replaced, that is, the toner empty state. Ru.

Then, by installing a new toner cartridge (15) containing sufficient toner, the toner empty state is resolved.

(2) Other Examples In the above description, the developing device (1) is equipped with two developing sleeves (37) and (39), but the present invention can also be applied to a developing device equipped with more sleeves. is applicable.

In the above embodiment, the flange (
53), the inclined part (53a
) to make the outer peripheral edge thin, but as shown in Fig. 7, the body of the flange (53) is made into a thin plate and the bucket (
Width T is attached to the part where 54) is attached, and the part (53c) is attached.
may be provided protrudingly.

Further, in the above embodiment, the developing sleeves (37), (39)
), the present invention is applied to a developing device that supplies toner into the flow of developing agent that is being conveyed on the surface of a developing sleeve. The present invention is applicable to six things.

Further, in the above embodiment, a case is shown in which a photoreceptor drum (+00) is used as an electrostatic latent image carrier. A device can be used.

(Effects of the Invention) As is clear from the above description, according to the present invention, since the thickness of the part of the bucket support body to which the bucket is not attached is thin, the developer is not easily absorbed by the bucket regardless of the thickness of the part to which the bucket is attached. Scraping is carried out efficiently, the scraping performance and transportability are improved, developer accumulation is prevented, and the torque of the drive device is not increased.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a developing device equipped with a bucket roller according to the present invention, FIG. 2 is a perspective view of the bucket roller according to the present invention, FIG. 3 is a perspective view of the bucket, and FIG. FIG. 5 is a sectional view showing the state of developer transport and agitation by the bucket at both ends of the bucket roller. FIG. 6 is a sectional view showing the state of developer transport on the developing sleeve. A partial perspective view, FIG. 7 is a perspective view of a bucket roller according to another embodiment of the present invention,
FIG. 8 is a sectional view of a developing device equipped with a conventional bucket roller. l...Developing device, 37.39...Developing sleeve, 46...Developer stirring tank, 51...Bucket roller, 53...Flange (bucket support), 54...
·bucket. Patent applicant Minolta Camera Co., Ltd. Representative Patent attorney Haka Aoyama Figure 7 Figure 8

Claims (1)

[Claims] (1) In the bucket roller of the developing device that takes in the developer collected from the developing sleeve, mixes it with the developer stored in the developer stirring tank, and supplies it to the developing sleeve, the bucket support of the bucket roller A bucket roller for a developing device, characterized in that the outer peripheral edge of the bucket non-attached part is thinner than the bucket attached part.